Test for cavitoma



United States Patent 3,157,470 TEST FOR CAVITOMA Charles M. Andrews, 927 Bradly, Lubbock, Tex. No Drawing. Filed Mar. 19, 1962, Ser. No. 189,371 6 Claims. (Cl. 23-230) This invention relates to testing cotton and more particularly to testing for damage done to raw cotton lint by Cavitoma.

In recent years a bacteria which damages raw cotton has spread over wide areas. The bacteria which damages the cotton has been called Cavitoma and the cotton so damaged has been described as Cavitomic cotton.

It is desirable to determine the amountv of damage which has been done to the cotton, so that work may proceed on a remedy for the problem. Also, merchants buying and selling cotton need some standard to determine the extent of damage to the cotton.

1 have found that if benzidine and some benzidine derivatives are applied to the cotton in an acidic aqueous solution that a yellow or yellow-orange color will result. The depth of color Will indicate the degree of damage.

An object of this invention is to provide a method to determine the damage done to cotton by Cavitoma.

Another object is to provide a method whereby the exact degree of damage by Cavitoma may be determined.

Another object is to provide a method which is accurate and not affected by other factors.

Further objects are to achieve the above with a procedure which is simple, and easy to perform by unskilled workers, yet is inexpensive to practice, all the time maintaining a high degree of reliability.

The specific nature of the invention as well as other objects, uses, and advantages thereof, will clearly appear from the following description.

One example of a method of practicing this invention is a solution prepared of water, one tenth of a percent (0.1%) benzidine (diaminodiphenyl-4,4) and two percent (2%) acetic acid, by weight.

Ten milliliters of the solution is poured over a onehalf /2) gram sample of dry cotton in a test tube and agitated with a glass rod. If the cotton is undamaged by Cavitoma, the solution will remain clear. If the cotton is damaged by Cavitoma, the solution will become a yellow, the solution becoming a darker yellow if the cotton is more heavily damaged. Within about 90 seconds, when the solution has become as dark as it will become, the solution is decanted into another test tube and the color of the solution compared against a standard color chart to determine the degree of damage according to a preestablished standard. About five minutes after it has reached its darkest yellow color, the color of the solution begins to dull.

It is possible to use 3,3'-dimethylbenzidine also called ortho-tolidine (3,3'-dirnethyldiaminodiphenyl-4,4) as the color agent rather than benzidine. However, 3,3-dimethylbenzidine does not give as good results as the benzidine. It works slower. It also is used in an acidic solution.

Also, 3,3-dimethoxybenzidine (3,3'-dimethoxydiaminodiphenyl-4,4') works as well as or better than benzidine as the color agent. On damaged cotton, it will result in a degree of deeper orange or brownish yellow color than benzidine. It also is used in an acidic solution.

One-tenth of one percent is an excess amount of color agent, an excess amount doing no harm. Lower concentrations take longer to react; higher concentrations, shorter.

The solution may be made with either acetic or hydrochloric acid or a mixture of the two. The optimum pH is about 2.5. If the pH is as high as about 4.5, it requires about minutes for the color to develop.

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The color develops more rapidly with lesser pH. With a pH of about 1.4 there is a reaction between the acid and color agent.

Once the acid and color agent are mixed, the color agent is converted to a di-acid derivative thereof. It hydrochloric acid and benzidine are used the resulting agent is diaminodiphenyl-4,4-dihydrogenchloride. Therefore, if desired this hydrogenchloride derivative may be used as a beginning agent. This is also true of the 3,3- dimethylbenzidine and 3,3'-dimethoxybenzidine. Also, the acetic acid derivative of each of the three color agents may be used.

3,3'-dimethoxybenzidine may be satisfactorily sprayed upon cotton. A typical method being one part benzidine (3,3-dirnethoxydiaminodiphenyl-4,4') is mixed with twenty parts acetic acid and one thousand parts water by weight. This solution is sprayed on dry cotton. Shortly the solution on the cotton will turn to a yellow or orange depending upon the Cavitomic damage to the cotton. If the cotton is undamaged by Cavitoma, the solution will remain clear. More heavily damaged cotton will turn the solution a darker color.

The solution may be sprayed upon the cotton by any convenient means. Use of a propellant such as a commercially available fluoride hydrocarbon is desired because a fine spray and deep penetration into the cotton is obtained.

When the solution is sprayed some benefits are derived by adding a wetting agent to the solution. Wetting agents are known to the cotton industry and they aid by reducing the surface tension of the solution so that it more quickly contacts the fibers. Also, they have a detergent action upon natural waxes of the cotton so that it is more quickly Wetted.

It will be apparent that the embodiments described are only exemplary and that various modifications can be made within the scope of the invention as defined in the appended claims.

I claim as my invention:

1. The method of testing cotton for Cavitoma damage comprising: contacting cotton With an acidic aqueous solution of a member selected from the group consisting of benzidine, 3,3'-dimethylbenzidine and 3,3'-dimethoxybenzidine, and the hydrogen chloride derivatives thereof and acetic acid derivatives thereof, observing the degree of color change in the solution which comes in contact with the cotton, and comparing the observed color change with standard colors which relate to the degree of cotton damage.

2. The method of testing cotton for Cavitoma damage comprising: contacting cotton with an acidic aqueous solution of a member selected from the group consisting of benzidine-dihydrochloride, 3,3-dimethylbenzidinedihydrochloride, 3,3 dimethoxybenzidinedihydrochloride, benzidinediacetic acid, 3,3 dimethylbenzidinediacetic acid, and 3,3' -dimethoxybenzidinediacetic acid, observing the degree of color change in the solution which comes in contact with the cotton, and comparing the observed color change with standard colors which relate to the degree of cotton damage.

3. The method of testing cotton for Cavitoma damage comprising: contacting cotton with a water solution containing acetic acid and benzidine wherein the pH of such solution is in the range of 4.5 to 1.4, observing the degree of color change in the solution which comes in contact with the cotton, and comparing the observed color change I with standard colors which relate to the degree of cotton damage.

4. The method of testing cotton for Cavitoma damage comprising: contacting cotton with a water solution containing acetic acid and 3,3-dimethoxybenzidine, the pH of the solution being in the theliegfee of 'colorchange in'the solution which comes in "contact with the "cotton, "and 'corrip'arifigdhe observed color change with standard colors which relate to the degree of cotton damage. l w H w 7 t I, V v

. Iheniethodof testing cotton for Cavitomw'dam'age comprising: contacting cotton with a waiterfsolutionj containing hydrochloric acid and benzidine, 'thejpH of the sollitioh'bcfiig ihutlie r'an'ge of 4.5 'to IA/blisrvingfthe degree of ,Eolorfch'ange'in the solution which comes in Contact with the cotton, and comparing the observed colorl chejng e standard colors 'which relzite to the degree of cotton damage.

range of 4.5 to 1.4, observing 6 Th e metl 1od of t estin' g cotton for Qayitorna daniage 15 comprising: contactingcotton with a'water solution of hydrochloric acid and 3,3'-dimethoxybenzidine, thepH "of the solution beingin the'range'of 4.5 to 1.4, observing the degree of, color change in the solution which comes in Contact with the cotton, and comparing the observed 9 4- color change with standard colors which relate to the degree of cotton damage.

References Cited in the file of this patent UNITED STATES PATENTS 2,905,594 Morris Sept. 22, 1959 3,066,081 Rorem et a1. Nov. 27, 1962 FOREIGN PATENTS Australia Feb. 22, 1929 

1. THE METHOD OF TESTING COTTON FOR CAVITOMA DAMAGE COMPRISING: CONTACTING COTTON WITH AN ACIDIC AQUEOUS SOLUTION OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF BENZIDINE, 3,3''-DIMETHYLBENZIDINE AND 3,3''-DIMETHOXYBENZIDINE, AND THE HYDROGEN CHLORIDE DERIVATIVES THEREOF AND ACETIC ACID DERIVATIVES THEREOF, OBSERVING THE DEGREE OF COLOR CHANGE IN THE SOLUTION WHICH COMES IN CONTACT WITH THE COTTON, AND COMPARING THE OBSERVED COLOR CHANGE WITH STANDARD COLORS WHICH RELATE TO THE DEGREE OF COTTON DAMAGE. 